Amkor Technology's stock fell 5.02% during the night session, as the semiconductor packaging and testing services provider announced a secondary offering of its common stock.

The decline came after the company announced that the Kim family, significant shareholders, would be offering 10 million shares of Amkor Technology common stock at a public offering price of $48.75 per share. Secondary offerings often lead to stock price pressure due to concerns about dilution and increased share supply in the market.

Despite the offering, the Kim family will continue to own over 49% of Amkor's common stock, maintaining their controlling interest in the company.